Proth Search Page

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Contents
 
Primes  k · 2n + 1  List of primes for k < 300
List of primes for 300 < k < 600
List of primes for 600 < k < 900
List of primes for 900 < k < 1200
Frequencies (draft)
History (under preparation)
Fermat numbers Standard factoring status  
Factors of generalized Fermat numbers  
GFN03 factoring status
GFN05 factoring status  
GFN06 factoring status
GFN07 factoring status
GFN10 factoring status  
GFN11 factoring status  
GFN12 factoring status
Search limits and reservations
Primes  k · 2n − 1  List of primes for k < 300
The Sierpiński problem   Definition and status  
The Riesel problem Definition and status  
Cullen primes Definition and status
Woodall primes Definition and status



Last modified July 31, 2019: 
Generalized Fermat number GF(25,10) proved composite.

July 15, 2019:
Lists of primes  k · 2n + 1  and  k · 2n − 1  updated:
all currently known primes included.
New factors at GFNfacs.html:
now includes 6618 new divisibilities (10 found in 2019).

July 6, 2019:
Generalized Fermat number GF(24,10) proved composite.

March 23, 2019:
New factor of Fermat number F(9863).

January 28, 2019:
New factor of Fermat number F(118).

December 19, 2018:
New factor of Fermat number F(132).

December 13, 2018:
New factor of Fermat number F(3345).

November 2, 2018:
New factor of Fermat number F(2144).

July 24, 2018:
New factor of Fermat number F(5199).
It brings to 300 the total number of known composite
Fermat numbers.

May 1, 2018:
New factor of Generalized Fermat number GF(10746,12).

April 5, 2018:
New factor of Fermat number F(274).

April 3, 2018:
Candidate of Extended Sierpinski Problem eliminated.

March 10, 2018:
New factor of Fermat number F(63480).

January 15, 2018:
New factorization at GFNsmall.html:
Cofactor of  11^(2^8) + 10^(2^8)  is  P62 × P107 .

December 30, 2017:
Riesel problem candidate eliminated!